Pluginfy RuboCop Minitest

This PR adds support for RuboCop's Plugin feature:
rubocop/rubocop#13792

It replaces the ad-hoc `Inject` with RuboCop plugins introduced in RuboCop 1.72.

Author: koic

Diff for: .github/workflows/test.yml

@@ -91,7 +91,7 @@ jobs:
         run: |
           sed -e "/gem 'rubocop', github: 'rubocop\/rubocop'/d" -i Gemfile
           cat << EOF > Gemfile.local
-            gem 'rubocop', '1.61.0' # Specify the oldest supported RuboCop version
+            gem 'rubocop', '1.72.0' # Specify the oldest supported RuboCop version
           EOF
       - name: set up Ruby
         uses: ruby/setup-ruby@v1

Diff for: .rubocop.yml

@@ -1,11 +1,13 @@
+# This is the configuration used to check the rubocop source code.
+
 inherit_from: .rubocop_todo.yml
 
-# This is the configuration used to check the rubocop source code.
+plugins:
+  - rubocop-internal_affairs
+  - rubocop-minitest
 
 require:
-  - rubocop/cop/internal_affairs
   - rubocop-performance
-  - rubocop-minitest
 
 AllCops:
   NewCops: enable

Diff for: README.md

@@ -30,24 +30,27 @@ ways to do this:
 Put this into your `.rubocop.yml`.
 
 ```yaml
-require: rubocop-minitest
+plugins: rubocop-minitest
 ```
 
 Alternatively, use the following array notation when specifying multiple extensions.
 
 ```yaml
-require:
+plugins:
   - rubocop-other-extension
   - rubocop-minitest
 ```
 
 Now you can run `rubocop` and it will automatically load the RuboCop Minitest
 cops together with the standard cops.
 
+> [!NOTE]
+> The plugin system is supported in RuboCop 1.72+. In earlier versions, use `require` instead of `plugins`.
+
 ### Command line
 
 ```sh
-$ rubocop --require rubocop-minitest
+$ rubocop --plugin rubocop-minitest
 ```
 
 ### Rake task
@@ -56,7 +59,7 @@ $ rubocop --require rubocop-minitest
 require 'rubocop/rake_task'
 
 RuboCop::RakeTask.new do |task|
-  task.requires << 'rubocop-minitest'
+  task.plugins << 'rubocop-minitest'
 end
 ```
 

Diff for: changelog/new_pluginfy_with_lint_roller.md

@@ -0,0 +1 @@
+* [#329](https://github.com/rubocop/rubocop-minitest/pull/329): Pluginfy RuboCop Performance. ([@koic][])

Diff for: docs/modules/ROOT/pages/usage.adoc

@@ -9,24 +9,26 @@ Put this into your `.rubocop.yml`.
 
 [source,yaml]
 ----
-require: rubocop-minitest
+plugins: rubocop-minitest
 ----
 
 Now you can run `rubocop` and it will automatically load the RuboCop Minitest
 cops together with the standard cops.
 
+NOTE: The plugin system is supported in RuboCop 1.72+. In earlier versions, use `require` instead of `plugins`.
+
 == Command line
 
 [source,sh]
 ----
-$ rubocop --require rubocop-minitest
+$ rubocop --plugin rubocop-minitest
 ----
 
 == Rake task
 
 [source,ruby]
 ----
 RuboCop::RakeTask.new do |task|
-  task.requires << 'rubocop-minitest'
+  task.plugins << 'rubocop-minitest'
 end
 ----

Diff for: lib/rubocop-minitest.rb

@@ -4,8 +4,5 @@
 
 require_relative 'rubocop/minitest'
 require_relative 'rubocop/minitest/version'
-require_relative 'rubocop/minitest/inject'
-
-RuboCop::Minitest::Inject.defaults!
-
+require_relative 'rubocop/minitest/plugin'
 require_relative 'rubocop/cop/minitest_cops'

Diff for: lib/rubocop/minitest.rb

@@ -1,11 +1,7 @@
 # frozen_string_literal: true
 
 module RuboCop
-  # RuboCop minitest project namespace
+  # RuboCop minitest project namespace.
   module Minitest
-    PROJECT_ROOT   = Pathname.new(__dir__).parent.parent.expand_path.freeze
-    CONFIG_DEFAULT = PROJECT_ROOT.join('config', 'default.yml').freeze
-
-    private_constant(:CONFIG_DEFAULT, :PROJECT_ROOT)
   end
 end

Diff for: lib/rubocop/minitest/inject.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require 'lint_roller'
+
+module RuboCop
+  module Minitest
+    # A plugin that integrates RuboCop Minitest with RuboCop's plugin system.
+    class Plugin < LintRoller::Plugin
+      def about
+        LintRoller::About.new(
+          name: 'rubocop-minitest',
+          version: Version::STRING,
+          homepage: 'https://github.com/rubocop/rubocop-minitest',
+          description: 'Automatic Minitest code style checking tool.'
+        )
+      end
+
+      def supported?(context)
+        context.engine == :rubocop
+      end
+
+      def rules(_context)
+        LintRoller::Rules.new(
+          type: :path,
+          config_format: :rubocop,
+          value: Pathname.new(__dir__).join('../../../config/default.yml')
+        )
+      end
+    end
+  end
+end

Diff for: lib/rubocop/minitest/plugin.rb

@@ -23,7 +23,8 @@ Gem::Specification.new do |spec|
     'source_code_uri' => 'https://github.com/rubocop/rubocop-minitest',
     'documentation_uri' => "https://docs.rubocop.org/rubocop-minitest/#{RuboCop::Minitest::Version.document_version}",
     'bug_tracker_uri' => 'https://github.com/rubocop/rubocop-minitest/issues',
-    'rubygems_mfa_required' => 'true'
+    'rubygems_mfa_required' => 'true',
+    'default_lint_roller_plugin' => 'RuboCop::Minitest::Plugin'
   }
 
   spec.files = Dir['LICENSE.txt', 'README.md', 'config/**/*', 'lib/**/*']
@@ -32,6 +33,7 @@ Gem::Specification.new do |spec|
   spec.executables = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
+  spec.add_dependency 'lint_roller', '~> 1.1'
   spec.add_dependency 'rubocop', '>= 1.61', '< 2.0'
   spec.add_dependency 'rubocop-ast', '>= 1.38.0', '< 2.0'
 end

Diff for: rubocop-minitest.gemspec

@@ -15,7 +15,7 @@ task update_cops_documentation: :yard_for_generate_documentation do
 
   # NOTE: Update `<<next>>` version for docs/modules/ROOT/pages/cops_minitest.adoc
   # when running release tasks.
-  RuboCop::Minitest::Inject.defaults!
+  RuboCop::ConfigLoader.inject_defaults!("#{__dir__}/../config/default.yml")
 
   CopsDocumentationGenerator.new(departments: deps).call
 end

Diff for: tasks/cops_documentation.rake

@@ -506,7 +506,7 @@ def style
   private
 
   def configure_enforced_style(style)
-    all_config = YAML.safe_load(RuboCop::Minitest.const_get(:CONFIG_DEFAULT).read).freeze
+    all_config = YAML.safe_load(File.read("#{__dir__}/../../../../config/default.yml")).freeze
     cop_config = all_config['Minitest/GlobalExpectations']
     cop_config = cop_config.merge('EnforcedStyle' => style)
     all_config = all_config.merge('Minitest/GlobalExpectations' => cop_config)